master-slave

问题 I setup an EC2 instance with MySQL on EBS volume and setup another instance which acts as Slave for Replication. The replication set up was fine. My question is about taking snapshots of these volumes. I noticed that the tables need to be locked for the snapshot process which may cause inconvenience for the users. So, my idea is to leave the Master instance alone and take a snapshot of instance acting as slave. Is this a good idea? Is there anyone out with a similar setup and could guide me

问题 I run a very simple MySQL database construct. I only have like id, TimeStamp and OP_fs155e columns which I consider is extremely basic setup. MariaDB [gadbdfm]> desc optical_power; +-----------+------------------+------+-----+----------------------+-----------------------------+ | Field | Type | Null | Key | Default | Extra | +-----------+------------------+------+-----+----------------------+-----------------------------+ | id_record | int(10) unsigned | NO | PRI | NULL | auto_increment | |

问题 I want to setup an ActiveMQ cluster. As I encountered problems with shared nothing approach, I'd like to do it using shared filesystem. However, the ActiveMQ documentation warns about possible problems related to filesystem locks. As I'm not sure, I'd like to ask, if GlusterFS would be a good choice for shared filesystem. 回答1: Shared-storage master-slave requires that the underlying file system supports network file locks. GlusterFS seems to support network locks going by the documentation

问题 Installed Jenkins on Linux machine and jenkins hosted on name say jiort04:8080. Created slave name it as mac-slave in Jenkins and launch method used it as Launch agent via Java Web Start Method and necessary configurations are added. However, it failed to connect to slave said logs and error attached below screen-shot. Log ` java.net.UnknownHostException: jiort04 at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) at java.net.SocksSocketImpl.connect(SocksSocketImpl

问题 I am picking up knowledge of consensus protocols in a distributed system. Such a distributed system does primary-backup on databases. I learned that "every consensus protocol can loop forever." from Leader election for paxos-based replicated key value store Where is the information source of "every consensus protocol can loop forever"? Status update: question answered. The same information source was provided by rystsov and another person of another post. Could more theoretical results and

问题 We have a separate RDS Instance to handle session state tables, however found that the session DB load is very low. if we can convert the instance handling session as a Read Replica of the main DB, then we can use it for read-only tasks that are safe even with a large lag in the copy. Has anyone done something like this on RDS (Is it possible and safe)? Should I watch out for any serious side effects? Any links or help in understanding this better would help. http://aws.amazon.com/rds/faqs/

问题 Does anybody have a working example of how to configure a cluster of nodes to share an index using the infinispan directory provider? All the documentation on Infinispan (the documentation is seriously lacking btw) implies that it should be as easy as having some properties set but no matter how I try I cannot get it to work. The nodes in the cluster find eachother fine and I can do get operations on one node and get object that were put on another. But as soon as I do queries (use the index)

问题 Want to set up mysql master-slave replications in rails app. Are there plugins/db adapters available for Rails 3? Does the Masochism plugin work properly with rails 3? 回答1: Try Octopus, which supports both rails3 and rails2.3: https://github.com/tchandy/octopus Masochism, DbCharmer, data_fabric et al will probably never be updated for Rails3 since so many ActiveRecord internals have drastically changed. 回答2: data_fabric also now claims support for Rails 3.0.7 https://github.com/mperham/data

问题 I get a permissions denied but don't know why. From my jenkins master I was able to run the following command using ssh-rsa-key scp /var/cache/jenkins/war/WEB-INF/slave.jar jenkins@<my_slave_host>:/var/jenkins/ Note: I did manually create /var/jenkins/ on the my slave host when i saw it didn't exist and made it owned by the jenkins user. My master jenkins is configured to use the jenkins@mySlaveHost using .ssh keys. Any ideas why I'm getting a permissions denied? What is it trying to do? Here

问题 I have 2 MySql with a master/slave configuration and the replication is failing. The MySql Master crashed and a new register in the mysql-bin.index was created. I deleted this new register because this file was not existed in the file system. Then the MySql Master restarted successfully. Now, I have the next error in the slave: mysql> show slave status \G *************************** 1. row *************************** Slave_IO_State: Master_Host: 10.64.253.99 Master_User: replication Master